Tube joining method and means

ABSTRACT

A portable carriage adapted to be mounted on a tubular workpiece is used to perform cutting operations followed by in place welding operations on such workpiece using two subassemblies interchangeably mounted on the carriage, one for cutting and one for welding. The carriage is rotatable around the stationary workpiece or may be held stationary while the workpiece rotates. After preliminary trimming, fusion welding is progressively accomplished in a circular path to join the abutting ends of the workpiece components.

llnited States katent Inventors Appl. No. Filed Patented AssigneesRoderick G. Rohrberg Torrance;

Don 1E. Harvey, Inglewood, both of Cnllll. 21,674

Mar. 23, 1970 Dec. 21, 1971 North American Rockwell Corporation; AirProducts and Chemicals, llnc. Allentown, Pa. part interest to eachOriginal application Feb. 23, 1968, Ser. No. 707,819,- now abandoned.Divided and this application Mar. 23, 1970, Ser. No. 21,674l

TUBE JOINING METHOD AND MEANS 1 Claim, 22 Drawing Figs.

US. Cl 29/482,

int. Cl $23k 1/20,

ll ield oi Search 29/475,

[56] References Cited UNITED STATES PATENTS 3,254,404 6/1966 Becker29/482 X 3,324,275 6/1967 Peignen 228/29 X Primary Examiner-John F.Campbell Assistant ExaminerRichard Bernard Lazarus Attorneys-William R.Lane, Charles F. Dischler and Harold I-I. Card, Jr.

AMSTRACT: A portable carriage adapted to be mounted on a tubularworkpiece is used to perform cutting operations followed by in placewelding operations on such workpiece using two subassembliesinterchangeably mounted on the carriage, one for cutting and one forweldingThe carriage is rotatable around the stationary workpiece or maybe held stationary while the workpiece rotates. After preliminarytrimming, fusion welding is progressively accomplished in a circularpath to join the abutting ends of the workpiece components.

PAIENIEB mm SHEU 10F W0 6 m w H 0 R 6 m R M n DON E. HARVEY ATTORNEYMimi-20mm [an 3628236 SHEET UEUF YO FIG. 4

INVENTORS RODERICK G ROHRBERG DON E. HARVEY A TORNE Y PATENTEB mew anSHEET UHF T0 5 m T m V m RODERICK G. ROHRBERG DON E. HARVEY PATENTED m2]ran SHEET BMW 30 INVENTORS RODERICK G. ROHRBERG DON E. HARVEY FIG.

ATTORNEY PATENTEU 0am zen SHEET 0E [1F 10 FIG. 9

RODERICK G. ROHRBERG DON E. HARVEY AT TORNEY PATENTEB m2] ran SHEET CEUF10 FIG. I2

INVENTORS RODERICK G. ROHRERG DON E. HARVEY \C & ATTORNEY PATENIEDnEmmn31 2 23 sum 07 0F 10 274 Q I: !a

{P v 56 I FIG. [3

I5 INVENTORS FIG. I4

RODERICK G. ROHRBERG DON E. HARE/E Y ATTORNEY PAIENTEU mm m SHEET 080?10 FIG. I90

INVENTORS RODERICK G ROHRBERG DON E. HARVEY FIG. I6 fig ATTORNEYPATENTEU BEEN an SHEH USUF 10 M m6 H m0 VR W6. m m w R DON E. HARVEYAORNEY PAIENIEMMEZMM 3,628,286 SHEU 10 0F $0 PROGRAMMER g fgg g POWERSOURCE POWER SOURCE POWER SOURCE ROLLERS MOTOR OSCILLATOR WIRE FEED ELEc moaE FIG. 20

l N VENTORS RODERICK G. ROHRBERG DON E. HARVEY ATTORNEY TUBE JOININGMETHOD AND MEANS This is a division of application Ser. No. 707,819filed Feb. 23, l968, now abandoned.

SUMMARY OF THE INVENTION According to an illustrative embodiment of thisinvention, compact, lightweight and portable combination tool 20 is usedto join adjacent tubular conduit sections 10 and 12 with their ends insubstantially mutual contact along a place of abutment 14 by a fusionweld nugget l6 progressively forming weld seam 18 as seen in FIG. 1.Tool 20 comprises frame or chassis 22 adapted to be supported on theworkpiece components by a plurality of rollers such as 24, 26, 28 and 30seen in FIG. 5. The stated rollers are adapted to move frame 22 aroundthe stationary workpiece components 10 or 12, or alternatively to rotatethe workpiece components while mounted within the stationary frame. Thelower rollers 28 and 30 are adjustable into a wide range of differentpositions to accommodate different sizes of workpieces as suggested bycross-sectional areas 32 and 34. Resilient biasing force to hold rollers28 and 30 in close continuous contact with the workpiece surface isprovided by adjustable torsion bars. Thus, for example, tor sion bar 36shown in FIG. 4 is adapted for rotation by jack screw 38 whereby movablelink 40 positions roller 30. Roller 28 is similarly mounted with itsseparate torsion bar, in a manner oppositely corresponding with thebiasing means shown for roller 28. Motor 42 contained within roller 30drives the same during the cutting and the subsequent weldingoperations, while roller 28 is similarly driven by a separate motormounted therewith.

Cutting tool subassembly 44 shown in FIG. 7 is removably mounted withincradle cavity 46 in frame 22 best seen from FIG. 3, and includes millingcutter 48 for trim cutting a tube end while frame 22 rotates around thetube.

Welding tool subassembly 54 shown in FIG. 8 is also releasablypositionable within cradle cavity 46 of frame 22 and comprises andelectrode 56 with appropriate wire feed, oscillation and positionadjustment means for progressive fusion welding on a workpiece whileframe 22 rotates about the same.

BRIEF DESCRIPTION OF DRAWINGS FIG. I shows a type of conduit connectionadapted to be precut and precision welded by the apparatus disclosedherein;

FIG. 2 shows a general perspective view of the apparatus disclosedherein operatively mounted on a workpiece component for trim cuttingprior to welding;

FIG. 3 is a perspective view of the main supporting frame from thewelding tool shown in FIG. 2;

FIG. 4 is an isolated view, partly in cross section, of a portion of thestructure shown in FIG. 3 and generally representing a view taken online 4-4 in FIG. 5;

FIG. 5 is an end elevational view, partly in cross section, of thesupporting frame shown in FIGS. 3 and 4;

FIG. 6 is a perspective view, partly exploded, of the structure shown inFIGS. 3, 4 and 5;

FIG. 7 is an end elevational view of a cutting head adapted for mountingin the frame shown by FIG. 3;

FIG. 8 is an end elevational view ofa welding head adapted for mountingin the frame shown by FIG. 3;

FIG. 9 is a general perspective view of the cutting tool subassemblyshown in FIG. 7;

FIG. 10 is an exploded view in perspective of the structure shown inFIG. 9;

FIG. 11 is an end elevational view, partly in cross section, of thestructure shown in FIGS. 7, 9 and 10;

FIG. 12 is a side elevational view, partly in cross section, of thestructure shown in FIGS. 9-11, inclusive;

FIG. 13 is a general perspective view of the welding tool subassemblyshown in FIG. 8;

FIG. I4 is an end elevational view, partly in cross section, of thestructure shown in FIG. l3;

FIG. 15 is a cross-sectional view taken generally through thelongitudinal center of the structure shown in FIG. 14;

FIG. 16 is an isolated view of the electrode mounting arrangement fromthe structure shown in FIGS. 13-15, showing the oscillation movementthereof and with portions of the oscillation subassembly omitted for thesake of clarity;

FIG. 17 is an isolated plan view of detailed structure for adjustingoscillation of the electrode in the structure shown by FIGS. 13-16,inclusive;

FIG. 18 is an exploded view in perspective of the welding toolsubassembly shown in FIGS. 8 and 13-17, inclusive;

FIG. 19 is an exploded view in perspective of the oscillation adjustmentdetailed structure shown in FIG. 17;

FIGS. 19A and 19B are diagrammatic representations of the oscillatingsubassembly of FIG. 19 in two different positions of adjustment, andFIG. 20 is an electrical schematic diagram of an illustrative circuitfor operating the structure shown in FIGS. l-l9.

DETAILED DESCRIPTION OF INVENTION It is a principal object of theinvention in this case to provide a compact, lightweight and portablecombination tool forjoining generally cylindrical workpiece portionssuch as tubular conduits or the like to each other at the adjoining endsthereof.

Another object in this case is to provide apparatus as stated in theabove object capable of use in crowded equipment areas involvingseverely limited working space.

It is a further object of this invention to provide apparatus as setforth in the above objects having a wide range of adaptability todifferent workpiece sizes and materials.

It is also an object in this case to provide apparatus as set forth inthe above objects whereby preliminary trim cutting operations andsubsequent in-place welding operations may be performed at precisely thesame workpiece location using the same tooling setup by interchangeablesubassemblies for each stated operation.

Referring to the drawings briefly described above and par ticularly toFIG. 2, portable combination tool 20 may be seen operatively associatedwith a relatively thickor heavy-walled tubing section 12. Combinationtool 20 is supported entirely on workpiece 12 and is operativelyassociated with suitable control devices (not shown) and appropriatepower sources such as electrical power unit 21. workpiece 12 may bevertical, horizontal, or in any other position of angularity andlocation, since the apparatus disclosed herein is particularly adaptedfor field use and is not limited to bench use. Workpiece 12 may be cutto any desired length by situating the tool on the workpiece so thatmilling cutter 48 will be positioned at the precise location wherecutting is desired. With tool 20 thus mounted, operation of cuttingwheel 48 in a manner described more fully below is accompanied bysimultaneous rotation of either workpiece 12 or tool 20, since tool 20is mounted for rotation relative to the workpiece about the centerlongitudinal axis of substantially cylindrical tube 12.

Following the cutting operation, another workpiece such as tube 10substantially corresponding in size with tube section 12 may be joinedto the newly cut terminal end of tube 12 by preplacing tube 10 inabutting contact therewith and replacing tool subcombination assembly 44by welding tool subassembly 54 shown in FIGS. 8 and 13-15, after whichwelding may be accomplished by rotation of tool 20 simultaneously duringwelding in a manner corresponding with its rotation during the cuttingoperation. Thus, tool 20 essentially comprises a chassis or frame 22shown in FIG. 3 having a cradle cavity 46 dimen sioned and adapted toreceive and contain either of the tool subassemblies 44 or 54. Frame 22essentially consists of two end portions 23 and 25 secured to twooppositely corresponding side portions 27 and 29 by a plurality ofscrews 31. Frame 22 is supported on the workpiece by four rollers 24,26, 28 and 30 mounted within the frame. Rollers 24 and 28 aresimultaneously movable for initial adjustment as required to mount toolon a particular size workpiece, while rollers 26 and 30 are similarlymovable in unison by a single adjustment mechanism described more fullybelow. The supporting, positioning and operating relationships describedin connection with rollers 26 and 30 also apply to rollers 24 and 28,respectively.

Thus, referring to FIGS. 4 and 5, for example, it may be seen thatroller 30 is adjustable to maintain rolling contact with workpiececonduit 34, and similarly adjustable for smaller diameter workpiecessuch as conduit 32 shown in broken lines. The foregoing adjustments areaccomplished by rotation of jackscrew 38 which generally comprises anelongate shaft rotatably mounted within a cavity 58 situated withinframe 22. .lackscrew 38 is provided with a plurality of worm gearthreads 60 operatively engaging worm gear pinions or pinion segments 62and 64 situated above and below jackscrew 38, respectively, in the viewshown by FIG. 5. Suitable means for preventing translational movement ofjackscrew 38 along its center longitudinal axis may be provided such assuggested by thrust sleeve 66 threadably secured within cavity 58 andoperatively related to flanged portions 68 and 70 of jackscrew 38. Asuitable bearing support of any appropriate type may be provided at thedistal end ofjackscrew 38 as suggested by bearing 72.

Initially considering adjustment of roller 28 by means of jackscrew 38,it may be seen from FIGS. 4 and 5 that rotation of jackscrew 38 resultsin rotation of worm gear pinion segment 64 which is secured to one endof torsion bar 36 contained within housing tube 37 which is affixed tolink 40 by a plurality of screws 39. Torsion bar 36 is supported bysuitable bearings for limited rotation within frame 22 such as suggestedby bearings 71 and 73. Torsion bar 36 is secured to housing 37 and henceto movable link 40 by appropriate means such as pin 74 whereby rotationof torsion bar 36 causes rotation of link 40 about a centerline 96through the torsion bar. Link 40 is provided with bearing support meansto permit its rotation relative to frame 22, such means illustrativelycomprising bearings 73 and 76. Rotation of link 40 produced by rotationof jackscrew 38 will continue until roller 30 mounted on the lower endof the link firmly contacts the surface of workpiece 34, for example,shown in FIG. 5, after which further rotation of link 40 is resisted.Roller 30 is mounted for rotation relative to link 40 by suitablebearing means such as suggested by bearings 78 and80 shown in FIG. 4.Roller 30 is rotated within the mentioned bearings by a drive motor 42,the output shaft 82 of which is pinned to the roller by suitable meanssuch as pin 84. Motor 42 is affixed to link 40 by housing meanscoaxially situated within roller 30 and comprising substantiallycylindrical sleeve 86 secured by threads 87 or other suitable means tohousing support means 88 which in turn is secured to link 40 by forcefitting or by one or more screws such as screw 90 shown in FIG. 4. Motor42 is force-fit or otherwise immovably secured within housing 86 whileoutput shaft 82 of the motor is supported for rotation relative tohousing 86 by bearing 92. Electrical power for motor 42 is supplied bysuitable means such as suggested by leads 94 connected with an externalpower source suggested in the schematic view of FIG. 20.

From the foregoing description and the structure shown in FIGS. 4 and 5,it will be understood that rotation ofjackscrew 38 causes rotation oftorsion bar 36 and link 40 until roller 30 contacts workpiece 34, afterwhich further rotation of jackscrew 38 produces rotation of the left endof torsion bar 36 in the view shown by FIG. 4, while the right end ofthe torthrough worm gear pinion segment 64. Due to the resilient biasingof drive roller 30 into contact with workpiece 34, the mentioned rolleris maintained in firm continuous contact with tubular workpiecethroughout the entire path of relative movement between tool 20 and theworkpiece in spite of such common workpiece discrepancies as local areasof flatness, ridges or roughness, and nonuniform diameter.

With further regard to the adjustments achieved by jackscrew 38, it maybe seen from FIGS. 4 and 5 that upper pinion segment 62 operativelyengages threads 60 on the jackscrew and is rotated about an axis 98 whenjackscrew 38 is rotated. Axis 98 coincides with the longitudinal axisthrough substantially cylindrical shaft 100 operatively associated withidler roller 26. Gear segment 62 is formed on shaft 100 whereby theshaft rotates when jackscrew 38 causes rotation of the gear segment.Shaft 100 is provided with suitable bearing supports at either endthereof to permit its rotation relative to frame 22, such as plasticbearing plugs 50 and 52 shown in FIG. 6. Plug 50 is shown in FIG. 4, andis rotationally supported within a hollow threaded cap 102 secured toframe 22. Shaft 100 is provided with a plurality of upstandingsubstantially parallel lugs or brackets 104, 106, 108 and 110 arrangedin pairs as seen from FIG. 6. Lugs 104 and 106, for example, have aspace or gap therebetween adapted to receive one end of a link 112 whichis pivotally associated therewith by suitable means such as pivot pin 1l4. Brackets 108 and 110 receive an end of link 116 which correspondsexactly in shape and function with link 112 and is pivotally secured tobrackets 108 and 110 by pin 118.

Referring to FIG. 6, it may be seen that roller 26 has an end closureplug 120 and 122 at each end thereof, and that the stated plugs areretained by a center shaft 124 threadably secured to the plugs byengagement within threaded holes in the center of each plug as indicatedby reference numeral 126 in FIG. 6. Each of the plugs 120 and 122 isprovided with an annular flange as shown by flange 128 on plug 120, thestated flanges being forced against the ends of roller 26 when items120, 122, 124 and roller 26 are assembled in operative relationship.Each of the plugs is further provided with a rotatable bearing surfaceadapted to contact a hole in each of the links to which the plugs arerespectively connected. The foregoing relationship is illustrativelyshown by bearing surface 130 on plug 120 which fits within hole 132 onlink 112 as suggested in FIG. 6, and by bearing surface 134 on plug 122shown in FIG. 4. On the distal end of each plug 120 and 122, oppositefrom the threaded connection joining the plugs to rod 124, is agenerally conical cam surface illustrated by surface 136 on plug 122seen in FIG. 4. Each of the cam surfaces thus provided at opposite endsof roller 26 is adapted to make rolling contact with a channel-shapedguide, one of which is designated by reference numeral 138 and isvisible in FIGS. 4 and 6.

Referring to FIG. 4, it will be understood from the structure showntherein and discussed hereinabove that rotation of jackscrew 38 causesrotation of gear segment 62 and bracketed tube 100. Movement of brackets104-110 resulting from rotation of tube 100 applies force to links 112and 116 through pins 114 and 118, respectively, whereby roller 26 movestoward or away from roller 24, in the view shown by FIG. 5. Thedirection of translational movement of roller 26 will depend upon thedirection of rotation of jackscrew 38 and gear segment 62, while thepath of such roller movement will be determined by the restraining sidesof guide elements 138 acting upon the cam surface 136 on each end ofroller 26.

As suggested hereinabove and shown by FIGS. 7 and 8, frame or chassis 22is adapted to receive and support two different types of tools inoperative relationship with the workpiece component upon which thechassis is supported. Thus, FIG. 7 shows cutting head 44 with millingcutter 48 rotatively mounted thereon, while FIG. 8 shows welding head 54with electrode 56 mounted thereupon and operatively positioned forwelding on workpiece component 12. As described more fully below,independent power means for the operation of cutter 48 and for electrode56 may be provided separate from the power means used to cause movementof chassis 22 about workpiece 12 during the cutting or weldingoperations.

Referring to FIGS. 9 and 10, it may be seen that cutting head 44comprises an outer structural housing 140 adapted to contain and supportan inner housing 142 within which is mounted a drive motor 144. Motor144 is connected to cutter 48 through a suitable gear train forreduction of speed as denoted by reference numeral 146 in FIG. 10, thecutter being secured to output shaft 148 by appropriate means such asholding nut 150 for securing the cutter to arbor 152. A suitableprotective cover such as cover 178 is provided over gear train 146 andsecured to housing 142.

Inner housing 142 is provided with an arcuate gear rack 154 which may beintegrally formed on the housing or removably attached thereto by boltsor the like. As shown in FIGS. 11 and 12, rack 154 is operativelyengaged by a pinion 156 supported on a shaft 158 mounted for rotationwithin housing 140 by suitable means such as bearing, bushings, or thelike. Rotation is imparted to shaft 158 through bevel gears 160 and 162,the latter being secured to the stated shaft, while gear 160 is securedto shaft 164 mounted within housing 140 and rotatable relative theretoby suitable provisions such as low-friction bushings 166 and 168 seen inFIG. 11. Rotation of shaft 164 is caused by manual force applied toadjusting knob 170 affixed to shaft 164 externally of housing 140.

As a result of the foregoing structural relationships, and due to thefact that the center of rotation of shaft 148 is close to the peripheryof substantially cylindrical inner housing 142 as seen from FIGS. 9-11,it will be understood that rotation of knob 170 causes rotation of innerhousing I142 relative to outer housing 140. Rotation of inner housing142 occurs about the center axis denoted by reference numeral 172 inFIG. 7, as a result of which, the axis of rotation of cutting wheel 48may be moved from the position designated by reference numeral 174 tothe position designated 176 in FIG. 7. Movement of the cutting wheel inthe stated manner advances the cutting portion of the wheel 48 closertoward the workpiece or move deeply within the workpiece material,whereby rotation of housing 142 by knob 170 in the foregoing mannereffectively determines the depth of cut subsequently resulting fromrotation of the cutting wheel. The adjustment thus achieved is made as apreliminary step while cutting tool subassembly 44 is supported withinframe 22 and prior to operation ofmotor 144.

Referring to FIGS. and 12, holding means are also included withinhousing 140 for securely holding inner housing 142 in any desiredposition of adjustment following positioning movement by knob 170 toachieve a desired depth of cut by cutting wheel 48. The stated holdingmeans include a strap or band clamp 180 essentially including a metallicstrap having two ends in closely confronting juxtaposition. The statedtwo ends may be moved close together or separated from each other byappropriate means such as a block or similar metallic mass secured toeach of the strap ends as suggested by blocks I82 and 184. At least oneof the stated blocks has a threaded hole therethrough adapted tooperatively engage a threaded shaft 186, whereby rotation of the shaftdraws blocks 182 and 184 closer together or separates them to result inapplication of clamping force by strap 180 around housing 142 or releaseof the same respectively. Shaft 186 is provided with a knob I88 mountedexternal to housing 140 whereby release of hoop tension in strap 180 maybe initially accomplished to permit rotation of housing 142 by knob 170prior to the start of the actual cutting operation. After initialpositioning of cutter 48 is complete, the final position of adjustmentis therefor maintained by turning knob 188 in the direction resulting intightening of band clamp 180 about the housing to hold the same in fixedposition relative to housing 140.

Provisions are further included in subassembly 44 for axial adjustmentof cutter 48 relative to frame 22 prior to the cutting operation.Referring to FIGS. 10 and 12. the stated provisions may be seen toinclude end closure element 190 which is secured to one end of innerhousing I142 by thread 192 in the manner shown. l-Iousing 142 istranslationally movable along its longitudinal axis relative to housing146, and force applied to element 198 is adapted to cause such movementwhen the component parts are assembled in operative relationship. Thementioned force is applied to element W8 by a knurled adjusting wheel194 which is supported on bearing 196 contained in a retaining cap 198which is joined to outer housing 142 by suitable means such as screws20'!) shown in FIG. 10. Wheel 194 is restrained against lateral movementdue to sliding surface contact on one side thereof with surface 286 ofretaining cap 198 and on the other side thereof with protective cover288 which is secured to cap 198 and housing by the mentioned screws 206.Due to the mentioned lateral restraint wheel 194, it will be understoodthat rotation of the wheel results in axial movement above end closureelement due to its threaded inner engagement with wheel 194 along thearea designated by reference numerals 210 and 212 in FIGS. 10 and I2.Translational movement of element 1190 in the foregoing manner resultsin similar movement of housing 142 to which element 190 is secured asdescribed above.

The cutting position of wheel 48 will be understood to depend primarilyupon the location at which frame 22 and cutting tool subassembly 44supported thereon are placed upon the workpiece. The means for laterallypositioning cutter 48 with respect to the workpiece described above willbe understood to constitute precision means for final adjustment of thecutter without necessitating movement of the entire supporting frame 22.

Referring to FIGS. 13ll8, a more detailed showing of welding toolsubassembly 54 may be seen than that shown by FIG. 8 briefly mentionedhereinabove. Thus. for example, welding tool subassembly 54 comprises aframe 220 having a lid 222 hingeably secured thereto for relativepivoting movement about a hinge center line 224 through a hinge pin 226.The various items secured to lid 220 include mounting means foradjustably supporting and for oscillating electrode 56, and wire feedmeans for continuously supplying weld metal into the puddle during thewelding operation. The detailed mounting arrangement for adjustablysupporting electrode 56 may be seen from FIG. 18 to include horizontalslide block 228 supported for translational movement relative to lid 222along two elongate guides of which only guide pin 230 is shown in FIG.18, 228 other being identical therewith and both passing through a pairof holes 232 in block 228 and secured at each end of the guide pinswithin holes 234 in. lid 222. Movement of horizontal slide block 228relative to stationary support pins or guides 230 is caused by adjustingknob 236 provided for this purpose and seen particularly in FIG. 15.Knob 236 is sup ported on slide block 228 for rotational movementrelative thereto by suitable means such as bearing support 238. Knob 236is further provided with beveled gear 240 operatively interengagingbeveled pinion 242 which is formed on the end of a threaded shaft 244.Shaft 244 is threadably engaged within a hollow cylindrical supportmember 246 which in turn is secured to lid 222 by suitable means toprevent its rotation such as pin 248. Because support member 246 isnonrotational and immovable with respect to lid 222, it will beunderstood that rotation of knob 236 and shaft 244 causes atranslational movement of the shaft which applies thrust to horizontalslide 228 causing lateral movement of the slide relative to lid 222 inthe view shown by FIG. 15, for example. The stated horizontal movementof slide 228 causes corresponding movement of electrode 56 which isindirectly mounted on horizontal slide block 228 by means which will nowbe described.

As seen particularly from FIGS. 14 and 18, horizontal slide block 228 isprovided with a plurality of pins 250, 252, 254, and 256, all of whichextend vertically downward from horizontal slide block 228 in the viewshown by FIG. 14. The mentioned four pins are operatively engaged with acorresponding number of holes in a vertical slide block 258 which istranslationally movable in a direction normal to the direction ofadjustable movement of horizontal slide block 228. Thus, pins 250, 252,and 254 are generally cylindrical guides slidably engaging holes 260,262 and 264, respectively. Force is applied to produce vertical movementof slide block 258 in the view shown by FIG. 15, for example, byvertical adjusting knob 266 which is formed or otherwise secured to theend of threaded shaft or pin 256. Pin 256 is rotationally mounted inhorizontal slide block 228 by suitable means such as bearing supportassembly 268 which allows rotation of the pin but prevents verticalmovement of the pin relative to slide block 228. Thus, rotation of knob266 and pin 256 causes vertical movement of slide block 258 relative tohorizontal slide block 228 and lid 222 by reason of the threadedinterengagement of pin 256 with hole 270 seen more particularly in FIG.18. The foregoing vertical movement of slide block 258 will beunderstood to cause corresponding vertical movement of electrode 56 inthe view shown, for example, by FIG. 15, because the electrode issupported on the vertical slide block as shown by FIG. 17 and discussedbelow.

Electrode 56 may be of conventional type such as used in tungsten inertgas (TIG) welding contained within a ceramic cup 272 in a manner knownto the prior art, the details of such mounting not being of significancein the inventive concept disclosed herein. Gas cup 272 and relatedinternal components is adapted for support on mounting block 274. Block274 is provided with a substantially cylindrical projection of tubularshape 276 mounted for reciprocal pivoting movement within suitablespaced-apart bearing support means 278 and 280 secured to vertical slideblock 258 shown particularly by FIGS. 17 and 18. The statedreciprocating movement of tube 276 relative to block 258 is transmittedthrough a block 274 whereby electrode 56 is likewise pivotallyreciprocated about the same rotation axis as tube 276 which coincideswith the longitudinal center axis 282 of the tube. Pivotal movement oftube 276 thus results in oscillating of electrode 56 as shown in FIG. 16and occurs by application of force to tube 276 in the manner now to bedescribed.

Referring to FIGS. 16 and 17, it may be seen that a generally C-shapedyoke 284 having flange portion 286 is secured to the hollow distal end288 of tube 276 by suitable means such as holding screw 290 and key 292which operatively interengages a pair of aligned grooves in tube 276 andhole 294 in the stated flange. Yoke 284 is further provided with a pairof spaced-apart projecting arms 296 and 298 adapted to lightly contactthe outer periphery of a circular bearing 300 at diametrically oppositelocations as shown in FIG. 16. Bearing 300 is operatively associatedwith an oscillating subassembly shown more particularly in FIG. 19.

Referring to FIG. 19, it may be seen that the oscillation subassemblyfor oscillating electrode 56 about rotation axis 286 includes a drivemotor 302 having a rotatable output shaft 304. Motor 302 is preferably avariable speed motor, and shaft 304 rotates in a uniform direction atsubstantially constant adjusted speed about a fixed axis of rotationthrough the center of the shaft. A generallycylindrical bushing 306 hasa nonconcentric hole 308 therethrough substantially corresponding insize with shaft 304 along a portion of its length and adapted to receivethe shaft in eccentric relationship with the bushing. Holding means toprevent relative movement between shaft 304 and bushing 306 may take anysuitable form, and in the illustrative case shown by FIG. 19, comprisesetscrew 310 threadably engaging hole 311 and adapted to bear againstshaft 302 whereby bushing 306 rotates with the shaft. However, forreasons described more particularly below, hole 308 is notconcentrically located in substantially cylindrical bushing 306 but isoffset from the geometric longitudinal center of the bushing. Bushing306 is further provided with a circular flange 312. Eccentric collar 314having three successive diametrically stepped cylindrical surface 316,318 and 320, is adapted to be mounted on eccentric bushing 306 by meansof hole 322 which passes completely through collar 314 and iseccentrically located relative to the geometric center of the collar.Hole 322 is sized to permit close sliding contact between the holesurface and the outer cylindrical surface of bushing 306. Collar 314 isrotatably movable about bushing 306 for a purpose described more fullybelow.

Resiliently biased holding means for holding collar 314 in any desiredposition of adjustment relative to bushing 306 is provided in thestructure shown by FIG. 19 in the form of detent ring 324 having aplurality of detents 326 diametrically spaced on one surface thereof asshown. Detents 326 are adapted to receive and retain a pair of radiallyextending ridges 328 on the surface of collar 314. Detent ring 324 isfurther provided with a diametrical groove 330 adapted to receive aretaining pin 332. A retaining cap 334 has a disc portion 336 adapted tobear against the surface of ring 324 and a center boss 338 sized to fitwithin opening 308 of bushing 306. A resilient ring 340 of suitablematerial such as a rubber O- ring is adapted to seat between the flatconfronting surfaces of detent ring 324 and disc 336 on the retainingcap 334. Boss 338 has a hole 342 therein sized and adapted to receiveretaining pin 332. Assembly of thevarious components shown in theexploded view of FIG. 19 begins with placement of bushing 306 on shaft304 and rotation of said screw 310 until the bushing is firmly securedon the shaft. Circular bearing 300 is seated upon surface 316 of collar314 and the collar is then placed on the bushing so that hearing 300 iswedged between flange 312 of the bushing and the flat lateral surfaceformed between cylindrical areas 316 and 318. Thereafter, detent ring324 is placed in contact with collar 314 and around bushing 306 so thatgroove 330 is aligned with a hole 344 in bushing 306 sized and adaptedto receive retaining pin 332. Ring 340 is placed against the flat endsurface of ring 324 and retaining cap 336 is placed against the ringwith boss 338 situated within hole 308 of bushing 306 with hole 342 inaligned under hole 344. With the parts thus assembled, retaining pin 332is placed through groove 330, holes 344 and 342, thus retaining theassembly in the operative relationship suggested, for example, in FIG.17. With the parts thus assembled in operative relationship, it will beunderstood that detent ring 324 is not rotatable relative to bushing 306due to the restraining influence of pin 332 lodged in diametral groove330 of the ring and through hole 344 of the bushing: However, collar 314is rotatably adjustable relative to bushing 306, and such rotation isdone manually such as by holding detent ring 324 stationary and applyingsufficiently great rotational force to surface 320 of the collar toovercome the compressive biasing force of ring 340 whereby radial ridge328 is forced out of lodgement within any one of detents 326 and intolodgement with another of such detents. In the absence of rotationalforce as required to adjust collar 314 in the stated manner, anydiametral pair of detents 326 holds collar 314 in a stationary positionof adjustment until the mentioned biasing force is again overcome bymanual rotation of the collar relative to ring 324.

Referring to FIGS. 10a and 1912, the effect of the foregoing adjustmentof collar 314 relative to bushing 306 may be seen. Thus, in FIG. 19a,the center of rotation of shaft 304 coincides with the geometric centerof collar 314 and this position of adjustment is identifiable with zerooscillation of electrode 56. FIG. 19b shows the position of adjustmentidentifiable with maximum oscillation of yoke 284 and electrode 56wherein collar 314 is rotated relative to bushing 306 so that thegeometric center of the collar is a maximum distance from the center ofrotation of shaft 304. In the foregoing position of adjustment, aperipheral point 346 on the edge of collar 314 will follow a circularrotational path indicated by dash line 348 having its center at therotation axis of shaft 304. The foregoing action will producereciprocating movement of yoke 284 about the axis of rotation 282 in themanner generally suggested by FIG. 16. The amount of distance which thelower distal end of electrode 56 will move in response to the foregoingeccentricity of collar 314 and bearing 300 mounted thereon will dependupon the relative distance between point 346 and the axis of shaft 304,as well as the relative distance between axis 282 and the lower distalend of the electrode.

Such distances, and their proportional relationship to each other, canbe varied in the size or selection of component parts to produce anyparticular amount of oscillation distance or dwell time desired for eachwelding operation involving use of the device disclosed herein. In anycase, however, it is of significance that the attachment of electricaland cooling water flexible conduits 350, 352 to block 274 as shown inFIGS. 14, 16 and 17 is located closely proximate axis,282, wherebymovement of such conduits even during maximum oscillation of electrode56 is'always minimized. Moreover, it may be seen from FIGS. 14 and 18that flexible conduits 350 and 352 enter welding tool subassembly 54through one end of hollow hinge pin 226 and exit through opening 354 inthe pin, further minimizing bends and stresses in the conduits whichwould otherwise result from movement of lid 222 in opening and closing.

With further regard to FIGS. 13, 14 and 18, it may be seen that weldingtool subassembly 54 also includes provision for feeding welding wire tothe vicinity of the weld puddle normally resulting from operation ofelectrode 56. The stated means include a spool 356 for supporting thecoiled wire 358, a variable speed motor 360 for driving spools withingearbox 362 at suitably adjusted speed to feed wire 358 through a guidetube 364 directed toward the mentioned weld puddle. The details of thewire feed system thus broadly suggested form no critical part of theoverall concept claimed in this case and accordingly need not be furtherdiscussed. Moreover, various means known to the prior art might beadapted to perform the functions of the foregoing wire feed system bythose skilled in the art without departing from the scope of theinvention disclosed herein.

Referring to FIG. 20, an illustrative arrangement for theelectromechanical relationship of the various detailed componentsdisclosed herein is schematically shown. Thus, separate power sourcesare preferably used for each of the components discussed hereinabove,operatively related by suitable circuitry to program control means 366which may comprise any one of several automatic welding control systemsknown to the prior art, the details of which form no part of theinvention claimed hereinbelow and accordingly need no further mention.

From the description set forth above in connection with the structureshown by the drawings, it will be understood that the combination toolthus disclosed in characterized by lightness, portability, and extremecompactness for operation within crowded installation as may be involvedfor in-place welding. Alignment of the device as required for precisecutting followed by precision welding is accomplished with great easeand direct visibility of the cutting or welding tool. The mountingsystem comprising rollers 24, 26, 28 and 30 adapts the combination toolto a wide range of different workpiece sizes and materials. The cuttingand welding operations are characterized by extreme rapidity, since nomajor readjustment of tool position is required or involved in theexchange of cutting tool subassembly 44 and welding tool subassembly 54in frame 22. Moreover, it may be seen from FIG. 5, for example, thatidler rollers 24 and 26 shown in contact with two different diameters ofworkpiece 32 and 34 are substantially in horizon tal alignment with eachother, whereby the arc gap between electrode 56 and either of the statedworkpieces will be substantially the same regardless of workpiecediameter. Fine ad justment of the arc gap is accomplished within thelimited range of movement permitted by translationally movable slideblocks 228 and 258. Many other functional advantages in addition tothose described above have been found to result from the structuredescribed herein. The space envelope around tube or 12 required forgyration of tool is relatively small, due to the fact that the tool isessentially wrapped around the workpiece in snugly gripping relationshiptherewith rather than rolled around a. track. Thus, the center axialcavity or passageway through mobile chassis or carriage 22 forms anarcuate vault within which tube 10 or 112 is automatically substantiallycentered when rollers 26, 26, 2b and 30 are moved into grippingrelationship with the workpiece. The

elongate or cylindrical shape of the rollers results in self-guiding ofthe chassis during its rotation about the tubular workpiece, since eachof the rollers contacts the tube along a straight line of contactparallel with both the axes of roller rotation and the centerlongitudinal axis of the workpiece. As a result, angular misalignment offrame 22 relative to the foregoing workpiece center axis is effectivelyprevented, whereas prevention of such misalignment would not result ifsmall wheels or the like were used instead of rollers to support frame22. Due to the stated self-guiding effect of straight line contactbetween the rollers and the workpiece, such contact should extend adistance at least as great as the diameter of the tubular workpiece, andpreferably a greater distance.

The restraint provided by guide elements 138 seen in FIGS. 4 and 6limits adjusting movement of idler rollers 24 and 26 to a common linearpath substantially normal to the rotation axes of both such rollers andresults in the surface of the tubular workpiece being in operativerelationship with two subassemblies 44 and 54 regardless of tubediameter, as suggested by tubes 32 and 34 in FIG. 5. Although slightvariations in arcing distance during welding operations with too]subassembly 54, for example, might result from drastic differences ofdiameter between different workpieces, the foregoing advantage of thestructure disclosed herein permits such minor variations to be easilycorrected by the limited adjusting movement of slide blocks 228 and 258as discussed hereinabove. The irreversible character of worm gear andpinion interengagement between jackscrew 38 and pinion segments 62 and64 results in positive holding force being applied to both segments evenwithout locking means on the jackscrews, whereby no lessening of holdingforce on rollers 24, 26, 28 and 30 can result from reaction loadsapplied to the pinion segments by the rollers.

While the particular details set forth above and in the drawings arethoroughly capable of providing the advantages herein stated, thestructure and method thus disclosed are merely illustrative and could bemodified or varied to produce the same results without departing fromthe scope of the inventive concept as defined in the appended claims.

We claim:

I. A method of automatically trimming and in-place welding tubularworkpiece components within closely confined areas, said methodcomprising:

supporting a frame on one of said components by cylindrical rollershaving parallel lines of contact with said one component, said linesfurther being parallel with the longitudinal center axis ofsaid onecomponent, mounting machine tool means on said frame in operativerelationship with said one component for cutting same,

rotating same frame on said rollers about said one component duringoperation of said machine tool means to progressively cut through saidone component on a plane normal to said center axis,

replacing said tool means by mounting welding tool means on said framein operative relationship for progressive fusion welding on said onecomponent,

placing another tubular workpiece component in axial alignment with andabutting said one component along said cutting plane, and

rotating said frame on said rollers during operation of said weldingmeans to progressively fusion weld said two workpiece componentstogether along a peripheral weld seam substantially defined by saidcutting plane.

1. A method of automatically trimming and in-place welding tubularworkpiece components within closely confined areas, said methodcomprising: supporting a frame on one of said components by cylindricalrollers having parallel lines of contact with said one component, saidlines further being parallel with the longitudinal center axis of saidone component, mounting machine tool means on said frame in operativerelationship with said one component for cutting same, rotating sameframe on said rollers about said one component during operation of saidmachine tool means to progressively cut through said one component on aplane normal to said center axis, replacing said tool means by mountingwelding tool means on said frame in operative relationship forprogressive fusion welding on said one component, placing anothertubular workpiece component in axial alignment with and abutting saidone component along said cutting plane, and rotating said frame on saidrollers during operation of said welding means to progressively fusionweld said two workpiece components together along a peripheral weld seamsubstantially defined by said cutting plane.